Computer data centers or computer servers generate large amounts of heat. Most data centers or servers currently use air to cool the computers or the components in the computer systems. Because of the increasing density of the components in the computer systems, the heat density of the computer systems and data centers is increasing.
The increase in heat density requires either higher air flow rates, cooler air, or both to adequately cool the system components. Cooling air to a temperature below the ambient temperature requires a refrigeration system. Refrigeration systems typically use large amounts of power. In fact, the refrigeration systems for a data center may use more than 50% of the total power required by the data center.
Some data centers use liquids as the heat transfer medium instead of, or in addition to, air. Liquids typically have a much higher heat carrying capacity than air. Unfortunately using liquids as the heat transfer medium can make it difficult to modify or replace components in the computer systems because the coolant lines may need to be opened and then re-sealed.